Means for improving the efficiency of turbines.



' No. 741,776. PATENTED 0GT.20,1903.

1. 11. DODGE. 7 7 MEANS 'I'ORIMPROVING EFFICIENCY OF TURBINES.

APPLIUATIQ II E D DEOflS, 1902K N0 MODEL. 3 SHEETS-SHEET 1.'

Witnesses: 7 nventor; 7 7 JqusLmRDodge, ZZYZ V HMM 4 No: 741,770.PATENTED 0GT.20,1903.

A. R. DODGE. 0 V MEANS FOR IMPROVING THE EFFICIENCY OF TURBINES.

LIO TION FILED 3 l 02 a SHEETS-SHEET 2.

N0 MODEL.

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-A. R; DODGE. MEANS FOR-IMPROVING THE EFFICIENCY OF TURBINESHAPPLIOATION FILED DEC. 13, 1902.

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no MODEL.

Inventor". flustinRDodge,

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UNITED. STATES ramm d October 20, 1903';

PATENT OFFICE.

AUs'rINR. DODGE,-OF,SOHENEOTADY, NEW Y K, ASSIGNOR 'TO GENERAL ELECTRICCOMPANY, A CORPORATION OF NEW YORK.

MEANS FOR: IMPROVING THEEFFICIENCY OF TURBINES.

SPECIFICATION forming part of Letters Patent No. 741,776, dated October20, 1903.

Application filed December 13, 1902. Serial No. 136,089- (No model.)

To aZZ whom it may concern:

Be it known that I, AUSTIN R. DODGE, a citizen of the United States,residing at Schenectady, in the county of Schenectady, State of NewYork,have invented certain new and useful Improvements in Means forImproving the Efficiency of Elastic-Fluid Turbines, of which thefollowing is a specification.

It is well known that in the elastic-fluid turro bines there isconsiderable moisture in the motive fluid and that the amount ofmoisture depends upon thecharacter of the turbine, and more especiallyupon the degree of expansion employed. By tests I have determined thatthe moisture in the motive fluid of the first stage of a two-stageturbine of the jet type working between absolute terminal pressure ofone hundred and sixty-five and one pound, whereinthe pressure of thefluid is largely converted into m's viva before being delievered to thewheel, com monly amounts to thirteen per cent. of the total weight ofthe fluid. The vaporis discharged from the last wheel or row of bucketson a wheel with considerable velocity, in some instances having avelocity of a thousand. feet per second. The vapor loses its velocity byimpact between the molecules in striking the shell or casing thatsurrounds the wheel or in striking some part within the shell, and on sodoing its energy is transformed into heat. This transformation of theenergy from One form to another causes a certain amount of the water dueto expansion and condensation to be reconverted into vapor. Thisreconversion, however, canonly take place at the expense of aconsiderable amount of thermal energy, which means a loss in efficiency.From actual tests it appears that with a turbine of the constructionspecified for every one hundred pounds of vapor delivered to it thereare thirteen pounds of water at the end of the first stage. It alsoappears that in passing into the second stage eleven pounds of thiswater are reconverted into vapor, thus leaving two pounds to mingle withthe steam. The steam in the second stage also has a certain percentageof moisture, due to its expansion, which is in addition to that alreadymentioned. The reconversion of water at this or any other point in theturbine calls for a considerable expenditure of thermal energy,- and alarge portion of the energy thus expend ed appears as latent heatin thesecond stage which performs no useful work.

The amount of moisture in an elastic-fluid turbine is less whereanon-expanding nozzle is used than an expanding nozzle; but in eithercase there is a substantial loss whenever there is a reevaporation ofthe moisture.

The advantages of using superheated steam or other vapor inelastic-fluid turbines to increase the efficiency are well known. It isacomparatively simple matter to supply superheated vapor to the firststage; but to supply it to a subsequent stage or stages presentsquiteadilferentproposition. Asbeforestated, the sudden checking orretardingof the stream of motive fluid under high velocity creates alarge amount of energy in the form of heat. Where there is aconsiderable percentage of moisture in the steam, this energyis expendedin reevaporation; but where the steam is dry, or practically so, theenergy can be ex pended in superheating. I make use of this condition ofafiairs in practicing my invention and provide a separator whichabstracts the moisture from the vapor while it is per-' forming usefulwork, after which the energy represented by the discharged vapor can beutilized for the purpose of superheating. By carefully separating themoisture from the steam at an intermediate point or points andsuperheating the steam the efticiency of the machine can beincreased anumber of per cent.

Efforts have been made in connection with reciprocating engines and witha fair degree ofsuccess to separate the moisture from the steam beforedelivering it to the cylinder; 0 but in so far as I am aware theseparator has always been placed in a conduit at some point where thesteam is doing no useful work. These separators are more or lessObjectionable on account of their bulk and also on 9.0- count of theadditional piping, all of which add to the costof installation. Broadlyspeaking, these separators are based on the idea of suddenly changingthe direction of the steamjet during the time that it is not performingIoc any useful work, thereby causing the water, which is heavier thanthe vapor, to be discharged into a receptacle specially provided. Theseparators are composed in certain instances of stationary parts and inother instances of moving parts or a combination of stationary andmoving parts. These have been placed between the boiler and the enginein some cases and between the high and low pressure cylinders in othercases.

The present invention has for its object to improve the efficiency of anelastic-fluid turbine by providing a means for separating the moisturefrom the motive fluid during the time that it is actually engaged inperforming useful work.

In so far as I am aware I am the first to ab-' stract moisture fromsteam or other elastic fluid during the time that it is acting on apiston or other moving body in a manner to perform useful work, and myclaims are to be construed as generic in this respect.

In carrying out my invention as applied to elastic-fluid turbines meansare provided at one or more points along the working passage whichreceive the stream of motive fluid, change its direction, and dischargeit against an adjacent vane or bucket. The same means may also act as aseparator and as a receptacle for the moisture which is separated fromthe main body of the vapor, the separation taking place on account ofthe sudden change in direction of the fluid stream.

In using the term working passage reference is made to the passagethrough which the motive fluid passes in going from one part of theturbine to another. In using the term in its broadest sense it refers tothe passage in a nozzle or to that between adjacent buckets and in amore limited sense it refers to both nozzle and bucket passages.

The separation of moisture from the vapor as it passes through theworking passage may be accomplished in several different ways. I mayprovide the intermediate buckets, which may be stationary or movable, asdesired, with water-receiving chambers and re stricted openings leadingthereto,or the wheelbuckets can be similarly constructed. I may alsoarrange one or more of the nozzles with moisture-separating means.Either of the means above specified can be used singly or incombination, as occasion demands.

I have described a means which is applicable to small-sized machines,where the volume of fluid to be handled is relatively small-- that is tosay, where the fluid passes through the machine as a single stream.Where the power of the machine is high, I find it desirable to subdividethe total volume of fluid into a number of streams, which while they mayform, in effect, a single stream can be treated, in so far as theseparation of moisture is concerned, as a number of relatively smallstreams, each of which is acted upon by one or more separators as itflows through the working passages.

In the accompanying drawings, which represent an embodiment of myinvention, Figure 1 is a partially-developed view of an elastic-fluidturbine. Fig. 2 is a longitudinal section taken on line 2 2 of Fig. 1.Fig. 3 is a cross-section of an intermediate and bucket-wheel. Fig. 4.is a partial longitudinal section of a bucket-wheel on aslightlymodified plan. Fig. 5 is a horizontal section of asingle-wheel-per-stage turbine. Fig. 6 is a perspective view of amodified form of bucket. Fig. 7 is a sectional view of' the bucket shownin Fig. 6. Fig. 8 is a partial view of an elastic-fluid turbine, showingmeans attached to the intermediate for abstracting moisture from themotive fluid. Fig. 9 is a partial view of a turbine, showing a meansapplied to the nozzle for abstracting moisture from the motive fluid.Figs. 10 and 11 are sectional details illustrating a modified form ofbucket construction.

Referring more particularly to Figs. 1 and 2, I have shown my inventionin connection with a prime mover. it takes the form of an elasticfluidturbine. It comprises a nozzle 1, which is adapted to deliver elasticfluid under considerable velocity to the rows of moving buckets 2, 3, 4,

and 5. These moving buckets are mounted upon the wheel 6, andconsequently move together, and, in effect, form a piston which is actedupon by the motive fluid in successive operations. Situated between therows of moving buckets are intermediate buckets 7 8 9. These buckets mayor may not be stationary, as desired. Each bucket is provided with achamber 10, that communicates with the working passage 11 between thebuckets by small openings 12. These openings may with advantage take theform of slits, as is more clearly shown in Fig. 2. The passage betweenthe stationary buckets forms a part of what I term the working passage,the said working passage comprising the nozzle and the various passagesbetween the wheel andintermediate buckets. Theintermediate buckets, inaddition to changing the direction of the stream of motive fluid anddischarging it against the adjacent wheel-buckets, act as a separatorfor abstracting moisture from the motive fluid as it passes through theworking passage- This feature of my invention is In the present instancebased on the general principle that moisture can be separated from steamor other elastic fluid by giving'to said elastic fluid a sudden changein direction, which causes the heavy particles, such as water, to beprojected into adifferent path from that taken by the lighter particles,which form the vapor. The fluid in the turbine has a velocity dependingupon the character of the expansion of the working passage. For example,it may be assumed that in the present instance the expanding nozzle 1discharges steam against the first row of wheel-buckets 2 with avelocity of two thousand two hundred feet per second, and as the motivefluid passes through the working passage formed by the stationary andmoving edthat is to say, at the first row of buckets it loses a certainamount of its velocity, at the second row of wheel-buckets it loses acertain amount more, and so on. As the steam or other elastic fluid isdischarged from the wheel-buckets against the intermediate buckets theparticles of water will strike the concave surface of one bucket and theparticles forming the vapor will be in contact with the convex surfaceof the adj acent bucket. The water which is collected in the chambers 10is carried off by the conduit 13, which is in communication with one ormore of said chambers. When the pressure of the steam in the workingpassage is above that of the atmosphere, the water will be blown out; ifit is below, the water can be removed in any one of the well-known ways.

Owing to the rapidity with which the steam travels through the workingpassage, it is difficult to abstract all of the moisture in oneoperation, and in order to do this I make all of the intermediatebuckets of the character previously described'-that is to say, eachbucket has a chamber with one or more perforations, which connect theworking passage with the chamber.

From the foregoing it will be seen that the energy is fractionallyabstracted from the motive fluid by the wheel and also that the moistureis fractionally abstracted from the motive fluid during such times as itis actually engaged in performing useful work.

The moving and stationary buckets are so arranged that they do notabstract all of the velocity due to the first nozzle from the motivefluid, and as the finid stream is discharged from the last wheel or rowof buckets, as the case may be, it is retarded by the bowl 1 of thesecond-stage nozzle. This retardation of the fluid stream changes itsenergy from that of motion into heat, and the heat thus produced isemployed in superheating the steam prior to its entrance into the secondstage or to an intermediate stage where more than two are provided. Thesuperheated steam passes from the bowl into the second-stage nozzle 1",where it attains the proper velocity prior to being delivered to thesecond-stage wheel. The buckets of the second stage resemble those inthe first; but by preference the area of the working passage is somewhatgreater to compensate for the increased volume and reduced pressure.Where only two stages are employed I may or may not use water-collectionchambers in the intermediates or in the wheel-buckets; but where morethan two stages are provided they will be found to be useful. As ageneral proposition it may be stated that the separators are usefulwherever there is any considerable amount of moisture due tocondensation and expansion, except in the case of the last stage, whichis connected to a condenser.

With turbines of low power it is satisfactory to deliver the motivefluid to the Wheel by a single nozzle or passage; but for higher to theaction of the separators, which ,is an important consideration.

In the drawings I have shown two sections of a nozzle, it beingunderstood that the figures are only partial views of a machine; but anynumber of sectional nozzles or passages can be employed to meet givenconditions.

Referring to Fig. 2, the intermediate buckets are mounted on a suitablesupport 14, which is provided with a flange 15, that is bolted orotherwise secured to the casing or shell 16, which surrounds the workingparts of the turbine. Each row of intermediate buckets is provided witha cover 17, which is situated between the detachable segmental pieces18, that carry the wheel-buckets. Each row of wheel-buckets is providedwith a cover 19, which may be made in sections or in a single piece, asdesired. These covers are situated between the supports for theintermediate buckets, with the exception of the two outer ones, whichare beyond the sides of the support.

Referring to Fig. 3, I have shown the intermediatebucketsinlongitudinalsection. For convenience of manufacture I have shown the intermediatesas being cast integral with each other; but, if desired, they can bemade separately and secured to their support in any desired manner. Thesupport 14, which is secured to the wheel-casing, is provided with asurface that is curved concentrically with the driving-shaft, andengaging with this surface is a corresponding surface formed on thedetachable intermediates. Each intermediate bucket is provided with achamber 10, that communicates by a passage 20 with a correspondingpassage 21, formed in the support 14. The passages 21 communicate withthe passage or conduit 13, and the latteris connected by pipes to theoutside of the wheelcasing. Each chamber communicates with the workingpassage by one or more slots or openings 12.

Referring to Fig. 4, the wheel-buckets are shown as being provided withchambers 22, (shown in dotted lines,) which arein communication with theworking passage by the slots 23. When the motive fluid is dischargedagainst the curved faces of these buckets, the water due to condensationand expansion passes through the slots intb the chamber, from which itis discharged throughthe peripheral opening 24 by the centrifugal actionof the wheel. The buckets can be made of castings, or they can be builtup, as desired,

the essential feature being to provide each a suitable receptacle.

bucket with means for separating the moisture from the steam anddischarging it into As shown, the buckets are mounted on segmentalpieces, which are secured to the wheel 6 by bolts that extend throughthe flange.

Referring to Fig. 5, I have shown my invention in connection with asingle-wheel-perstage turbine, wherein 25 represents a nozzle that maybe of the expanding or non-expanding type, as desired. Situated in frontof the nozzle is a wheel 27, having working passages 28 formed near itsperiphery. The form of this passage is similar to that described inconnection with the previous figures. The fluid from this wheel isdelivered to an intermediate 29, that is detachably secured to adiaphragm 30, formed in the wheel-case. In addition to acting as a meansfor receiving fluid and changing its direction the intermediate alsoacts as a nozzle in that it gives to the motive fluid a certainpredetermined amount of expansion. Each intermediate is also providedwith a water-receiving chamher, which chamber connects with the workingpassage by slots 31. In the present figure the slots are on the oppositeside of the bucket from the observer. Hence they are shown in dottedlines. The chambers of the several intermediate buckets are connected tothe passage 32, and the latter is connected to a pipe by means of whichwater is carried to the outside of the wheel-casing.

Referring to Figs. 6 and 7, I have shown a further modification of myinvention wherein the separator is formed as a separate part and isapplied to the buckets, which may revolve or not, as desired. 33represents a bucket which is formed integral with its support 34, andthe upper end thereof is provided with a tenon 35, by means of which thecover 36 can be secured in place. Covering the front or working face ofthe bucket is a thin sheet-metal plate 37, which may or may not bedetachable, as is desired. In the present instance it is secured to thebucket by small rivets 38. Between the plate and the main body of thebucket is a collection-chamber 39, which corresponds in all respects tothe chamber 10 formed in the intermediates and the chambers 22 in thewheel-buckets. The plate is perforated at a number of points 40, and inpunching these plates the bur 41 acts as a means for holding the plateaway from the front face of the bucket. A construction of this kind isdesirable because the faces of the buckets that are cut from solid stockdo not have to be so finely finished and, again, in case of wear theplates can readily be renewed. The chamber 39 registers with the opening42 in the bucket-cover, and owing to the centrifugal action of the wheelthe water due to expansion and condensation is thrown outwardly awayfrom the working passage, where it is collected by any suitable means.

Referring to Fig. 8, I have shown a further modification of my inventionwherein a nozzle 43 of the non-expanding type is provided having theusual bowl 44. A nozzle of this character imparts a greater or lessvelocity to the steam, depending upon the difference in pressure betweenthe bowl and the shell or between adjacent shells. Manifestly when anon-expanding nozzle is used the moisture in the vapor due to theexpansion is less than where an expanding nozzle is used; but there isstill considerable moisture which it is desirable to remove from themotive fluid. In connection with this type of nozzle I may abstract themoisture fractionally by means of separators formed in the intermediatesor by separators formed in the wheel-buckets. I have shown, however, aslight modification wherein a series of buckets 45 are provided whichact as separators for abstracting moisture from the steam, but do notact to deliver it to the bucket-wheels, this being taken care of by aseries of passages or nozzles 46. These nozzles may be of the expandingor non-expanding type, as is desired. In constructions of this kind thepassages 46 may be formed in a diaphragm 47, and the support 48,carrying the buckets 45, secured thereto, or the support 48 may carrythe piece 47.

In Fig. 9 I have shown a further modification of my invention wherein aseparator is applied to the nozzle 49, which may or may not be of theexpanding type, as desired. In this case, however, as in thosepreviously mentioned, the abstraction of the moisture from the motivefluid takes place while the latter is flowing through the workingpassage, it being understood, of course, that the work done by the steamcommences when it enters the nozzle. Bolted or otherwise secured to thedischarge end of the nozzle is a piece 50, containing one or moresegmental working passages 51 and a chamber 52, which communicates withthe working passage by means of small slits or openings 53. Water fromthe chamber is carried away by means-of the passage 54.

Where the separation is accomplished by stationary means, the pressureof the fluid stream is sufficient to blow the water out of the chamber;but the openings 53 should be small enough to prevent any appreciableleakage of the motive fluid. Two nozzles are shown in the presentinstance, but more can be employed, if desired. The intermediates 55 areshown as being arranged to act as separators; but it is evident that Imay use the wheel-buckets for this purpose.

Referring to Figs. 10 and 11, I have shown a means whereby existingbuckets can be arranged to operate in accordance with my invention. Thisis accomplished by drilling holes 56 in the bucket near the front faceand connecting said holes with the front face by means of narrow slots57. The upperend of each bucket is provided with a small chamber 58,into which the openings 56 deliver their contents. The openings 56 andthe chamber 58 have the same functions and operate in.the same manner asthe chambers and passages previously referred to. The buckets areprovided. with covers 59, and formed in the covers and registering withthe chambers 58 are openings 60, through which the water can beprojected under the centrifugal action of the wheel.

My invention is shown in connection with turbines designed to work withor without condensers, and I desire to be understood as including suchuses in the appended claims.

In accordance with the provisions of the patent statutes I havedescribed the principle of operation of my invention, together with theapparatus which I now consider to represent the best embodiment thereof;but I desire to have it understood that the apparatus shown is onlyillustrative and that the invention can be carried out by other means.

What I claim as new, and desire to secure by Letters Patent of theUnited States, is-

1. In an elastic-fluid motor, the combination of a working passage forthe motive fluid with means acting on the fluid in said passage while itis performing work for abstracting the moisture therefrom.

2. In an elastic-fluid motor, the combination of a revolving wheeldriven by the fluid with a means acting on the fluid stream while it isperforming work for abstracting moisture therefrom.

3. In combination, a prime mover operated by elastic fluid underpressure, with means acting on said fluid two or more times insuccession during the interval that it is performing useful work forabstracting the moisture therefrom.

4. In a prime mover operated by elastic fluid under pressure, thecombination of a piston which is acted upon two or more times insuccession by the motive fluid, with means acting on the fluid when itis performing useful work for abstracting the moisture therefrom.

5. In an elastic-fluid motor, the combination of a working passage forthe motive fluid, with means acting on the fluid in said'passage two ormore times in succession for abstracting the moisture therefrom.

6. In an elastic-fluid turbine, the combination of a working passagecomposed of moving and stationary parts, with a means for changing thedirection of the fluidstream and also separating the moisture therefrom.

7. In an elastic-fluid turbine, the combination of a working passagecomposedof moving and stationary parts, means for abstracting moisturefrom the fluid as it passes through said passage, and means forcollecting the moisture thus abstracted.

8. In an elastic-fluid turbine, the combination of a working passagewhich is subdivided into a number of smaller passages with separatemeans acting on the fluid as it passes through each of the smallerpassages for abstracting the moisture therefrom.

9. In an elastic-fluid turbine, the combination of a working passagecomprising moving and stationary parts, with means carried by thestationary parts for changing the direction of the fluidstream andabstracting the moisture therefrom.

10. In an elastic-fluid turbine, the combination of a working passagecomprising moving and stationary buckets, means acting in conjunctionwith the stationary buckets for changing the direction of the fluidstream and also for abstracting moisture therefrom, and a conduit fordrawing off water from said means.

11. In a prime mover, the combination of a piston that is acted upon bythe motive fluid two or more times insuccession, means for receiving thefluid after it has once acted on the piston and discharging it againstthe piston a second time, and means acting on the fluid stream as itpasses through the prime mover for abstracting the moisture therefrom.

12. In an elastic-fluid turbine, the combination of a bucket-wheel, apassage for discharging fluid against the wheel, and chamberedreceptacles which assist in conveying the fluid and abstracting themoisture from the fluid.

13. In an elastic-fluid turbine, the combination of a wheel, a passagefor discharging fluid against the wheel, and buckets eachhaving anexternal face that directs the motive fluid in its passage through theturbine and a chamber for collecting moisture from the vapor.

14. In an elastic-fluid turbine, the combination of a wheel, a nozzlefor discharging fluid against the wheel, buckets for directing thepassage of motive fluid and abstracting moisture therefrom, and meansfor collecting the moisture from the buckets.

15. In an elastic-fluid turbine, the combination ofa means forconverting a certain portion of the pressure of the motive fluid intovelocity, means for abstracting the velocity fractionally, and means forseparating the moisture from the vapor during the period that thevelocity is being abstracted.

16. In an elastic-fluid turbine, the combination of an expandingnozzle,'two sets of buckets situated in front of the nozzle andcooperating to fractionally abstract the velocity from the motive fluid,and a means acting on the fluid while it is performing useful work forabstracting the moisture from the elastic fluid.

17. An elastic-fluid turbine having chambered buckets between which theworking passages are formed, each of said buckets being provided withopenings in its Wall which connect the working passages with thechambers in the buckets.

18. As an article of manufacture, abucket for an elastic fluid turbine,comprising a curved wall for receiving motive fluid and changing itsdirection, which wall is perforated, and a chamber which is incommunication with said perforations.

IIO

19. In an elastic-fluid turbine, the combination of a fluid-dischargingpassage, rows of rotary buckets situated in front of said passage,chambered stationary buckets situated between the rows of rotary bucketswhich act as separators, and means for collecting the moisture from thechambers of the stationary buckets.

20. In combination, a means for dividing'a body of elastic fluid intotwo or more streams, with means simultaneously acting on the severalstreams for separating the moisture from the vapor.

21. In combination, a means for dividing a body of elastic fluid intotwo or more separate streams, means for changing the direction of flowof the several streams, and means acting on each of the streams forcollecting the moisture from the fluid.

22. In combination, a fluid-carrying passage, With means acting on thefluid body two or more times as it flows through the passage, forfractionally abstracting the moisture therefrom.

23. In combination, a means for dividing a body of elastic fluid intotwo or more streams, with means acting on each of the streams two ormore times in succession, for fractionally abstracting the moisturetherefrom.

24:. In an elastic-fluid motor, the combination of a fluid-dischargingnozzle, a piston which is acted upon by the fluid, means for abstractingmoisture from the fluid stream, means for converting the velocity of thefluid stream into thermal energy for superheating .the fluid, and asecond piston which is acted upon by the superheated vapor.

25. In an elastic-fluid turbine, the combination of an opening fordischarging fluid under high velocity, wheel-buckets situated in frontof the opening for abstracting a part only of the velocity of the fluidstream, a means for abstracting moisture from the fluid, a means forconverting the residual velocity of the vapor stream into heat after ithas left the buckets, a second fluid-carrying passage, and abucket-wheel situated in front of the passage.

In witness whereof I have hereunto set my hand this 12th day ofDecember, 1902.

AUSTIN R. DODGE.

WVitnesses:

EDWARD WILLIAMS, J12, ALEX. F. MACDONALD.

